Inhibition of rat recombinant PDE10A expressed in baculovirus infected insect Sf9 cells using [3H]cAMP as substrate after 60 mins by scintillation counting
Inhibition of rat recombinant PDE10A2 expressed in baculovirus infected SF21 cells using [3H]cAMP as substrate after 60 mins by scintillation proximity assay
Inhibition of recombinant rat PDE10A expressed in baculovirus infected insect SF9 cells using [3H]-cAMP as substrate after 60 mins by scintillation proximity assay
Inhibition of rat recombinant PDE10A expressed in baculovirus infected Sf9 cells using [3H]cAMP as substrate after 60 mins by TopCount scintillation counting analysis
Enzyme Inhibition Assay: An IMAP TR-FRET assay was used to analyze the enzyme activity (Molecular Devices Corp., Sunnyvale Calif.). 5 μL of serial diluted PDE10A (BPS Bioscience, San Diego, Calif.) or tissue homogenate was incubated with equal volumes of diluted fluorescein labeled cAMP or cGMP for 60 min in 384-well polystyrene assay plates (Corning, Corning, N.Y.) at room temperature. After incubation, the reaction was stopped by adding 60 μL of diluted binding reagents and was incubated for 3 hours to overnight at room temperature. The plates were read on an Envision (Perkin Elmer, Waltham, Mass.) for time resolved fluorescence resonance energy transfer.
Scintillation Proximity Assay: The ability of a compound to inhibit PDE10 enzymatic activity can be demonstrated by any number of assays that are known in the art. The products of Examples 1-175 were tested in the assay described below.PDE10 activity was measured using a scintillation assay (SPA-based method) similar to that previously described by Seeger, T. F. et al., Brain Research 985 (2003) 113-126. The compounds' relative activity as PDE10 inhibitors was investigated by assaying a fixed amount of enzyme in the presence of the test compound and low substrate concentration (cAMP) such that an IC50 could be determined. More specifically, this assay uses a Scintillation Proximity Assay (SPA) to measure the inhibition of rat1 and human recombinant2 PDE10 enzyme activity by compounds in vitro (preparation of enzymes described below). The assay is performed in a 384-well format with 50 uL assay buffer (50 mM TRIS pH 7.5; 1.3 mM MgCl2; 0.01% Brij) containing enough PDE10.